Tool for removing boiler-scale.



n. H. SMITH;

TOOL FOR REMOVING BOILER SCALE.

1,177,363. I I Patented Mar. 28,1916.

ATTORNEY UNITED STATES PATENTOFFICE- mm HALEY SMITH, or BANKHEAD,ALBERTA, CAKADAL rooL Foe IiEMovING'Bonne-soALE.

Application filed May 19, 1915. Serial No. 29,207.

Dominion of Canada, have invented, a new and Improved Tool for RemovingBoiler,- Scale, of which the following is a full, clear, and exactdescription. I

My invention relates more particularly to a pneumatic hammer forremoving boiler scale, and it is so constructedthatit can be used whereit is impossible to work eflectively and conveniently with chisel barsor a hand hammer.

The invention is characterized by a float-' ing chisel positioned in thebody of the pneumatic tool in front of the hammer, to be} struck by thelatter, the chisel being arranged to recede with the hammer under'thepressure of thetool against the work. The

body of the hammer is intwo parts united bv'a threaded'connectio'n, thefront mem-z her being in the form of'a ring that clamps thefcylinder andthe cover plate thereof in position and serves to retain the floatingchisel against displacement.

The invention will be particularly explained in the specific descriptionfollowing. Reference is had to the accompanying drawings forming part ofthis specification, in which similar characters of reference indicatecorresponding parts in all theviews, and in which: Figure 1 is alongitudinal section on the line '11 of Fig. 3; Fig. 2 is a similar viewwith the hammer and chisel in different positions in Fig. 1; and Fig. 3is a cross-section on the line 33 of'Fig. 1. V In constructingapractical embodiment of myinvention in accordance with the illustratedexample, thebodv of the tool is in two separate members. the back member10 forming the cylinder ofthe pneumatic hammer' and being united to thefront end 11 thereof by a threaded connection as at 12. At one side ofthe body is a tubular handle member 13 which in practice will receive a'handle of proper length and shape for the convenient manipulation'of thetool.

\Vithin the body is a cylindrical bushing 14 in which operates a pistonpresenting upper and lower piston heads 15. 15. A front cover plate16'is cla'mpedat the front of the cylindrical bushing between the'bodysections 10, 11,- said cover plate being en- Specification of LettersPatent.

Patented Mar. 28, 1916.

gaged by an annular internal shoulder 17 l on the front ring section 11of'the body. Infront of the cover plate *16'is a floating chisel 18presenting suitable cutting members 19 on its working face, there beingan annular flange '20 onthe chisel'outside of the working face, in therear thereof, which is retained against displacement by an internalannular flange 21 on the body section 11. Y

The cover plate 16 has-a central opening 22 through which the hammer 23carried by the piston isadapted to be operated to deliver a' blowagainst the inner face of the chisel 18. The said c'hiselhas a limitedreciprocating movement between "the front plate'16 and the flange 21 andis adaptedto be projectedbeyond the body by a blow of the hammer 23 whenthe front of the body;

and the working face of the tool are pressed against a side of theboiler surface to remove the'scale from the latter., The pressure of thetool against the work will cause the float,- ing chisel-to recede as thehammer recedes and be in a position tore'ceive an effective blowof'thehammer on the forward strike v of the latter. Y

Anyfapproved arrangement of inlet ports and exhaust ports may beprovided'in the cylindrical bushing 14, to be controlled by the pistonacting as a valve. In the illustrated form an annular chamber 24 betweenthe front and rear piston heads315, l5 'is in communication with thetubular handle 7 member 13, whichis connected in practice with a'compressed air supply or equivalent source of fluid pressure. Thebushing 14 is formedwith a lateral port'25 which communicates with'arearwardly. extending port 26 which in turn communicates with a lateralport 26 leading to the rear side of the back piston head 15.- A secondtransverse port 27leads from the cylinder and a, for-' wardlv extendingport 28 leading from the port 27 communicates with a lateral p'ortd.

28 at the front of the piston head 15. The exhaust from the back ofthe'pistonhead 15" discharges through a" lateral port 29?,and aforwardly extending exhaust port 29, which extends through the bushingand through the front cover plate 16 to discharge the exhaust through apassage 31 extend ng forwardly from the back of the chisel 18 to thefront of the latter, so that the exhaust will serve to blow chippedscalefrom in front of the tool. 'In the present example there ioo is adepressioni tl'ithe front offnthe cover plate l6""t"o which the exhaustpassage 29" leads and an annular depression 30 in the opposed rear face'of-the chisel surface to maintain communication between the exhaustport 29 and the passageportSl in the chisel. The fluid from in front ofthe piston head 15exhausts through the central opening 22 in the plate16 when the chisel is in the rearward position and thus through thedepressions 30,-..31, and discharges to: and.

througnthe passage 31'.

In assembling. the parts, therchiselwis dropped into the body section1].. The cover plate-16 is then placed in the=said body, to lie on theannular'shoulder. 1,7 thereof,and

, thepistonand ,cylinder bushing havingbeen placed in position in thebodyseotiomthe two sections are unitedby threaded. connection's;;12.,iThe-arrangement permitsof the ready 'dismembering ,of the tool forcleaning, or for. the repairor renewal of particular parts, theconstruction being particularly advantageous in permitting the readysharp-- ening of the chisel 18 The/tool is particularly useful inmanysituationswhere the: usual chisel bars. and handhammer cannot bei usedwith convenience or advantage.-

It.is;to.. be observedithat the flange has a beveled: forward surface20* extending annularly around the'same, and'a reverse bevelQO?rearwardof said front bevel;,also that the flange 21 ofthe=casingsection 11 has a bevel 21 mating thebevelQO of the chisel.

self,lwithout binding or jamming, to varying'conditionsin workingatdilferent angles.

to the boiler plate.

Having thus describedjmy. invention, what I [claim as newrand desire ito secureby Letters Patent, 11s:

1.. A- fluid: operated tool. comprising a body, a piston insaidbodycarrying a hammer, a-cylinder in the body in which the piston. operates,said cylinder having ports for theinlet and exhaust of. a motive fluid,-and' a floatingchisel separatev from and in front of the hammer and.arranged-to have a reciprocating movement in the body and forming aclosure of said body. at the front,

said workingtool having a forwardly extending passage therethrough vandin communic'at'ion with. the exhaust ports for the discharge of theexhaust fluidat thefront of the chisel;

floating, chisel inffiontof the cover. plate These-beveled surfacesallow the floating chisel freedom to accommodateits v and hammer,adapted towreceiverblbwsa of,

plate and the front member of the body,'said 7 w coverplatebeing clampedby the said front member of the body, and the chisel being. retainedagainst forward displacement by thesaidafront member.

3. In a fluid operated tool, a body having a tubular handlewherebyto..manipulatezthei; tool: and to conduct;motiveifluitbtlieretopai cylindrical bushingainthe body" engaging: with the.said-tubular= handle; said. bushing? being formed. with: inlet,- and.exhaust: ports-$ a piston operating. in; said bushing andlca rying, a'hammer,21a cover plate. in; front the bushing and havingopeningszcommuineating with "the exhaust: ports of the. bushing,n. the cover; plateproject therethrough,and-, a:floatingg1chisele in. front of the scover'plate andhammeri adapted to receive the blow-of the latter 'andiprovided with a discharge passageffor. thee exhaust.-. s H 1 I 90.1 4 Ina" tool ofthecharacter described;,aaI

body provided with means to supply; a-z-mow tive fluid,.acylindrical,bushingein the body a piston operating in the; bushing and:pro

vided witl .a hammer, inlet portscommunit 95,

eating with. the: fluid supplyandleadingiim opposite directions to :theback-and front of; I

the-piston, an. exhaust port-leading from; the back of the pistonforwardly, a cover iplaaten having an exhaust; port.-iin communieation'10o' with the exhaust portx fromtthetbaclr.of;the piston and havinga central!opening through which the hammer. projeets,,said-. opening:forming. an exhaust .from the-front; of-ith piston when thehammer-.;recedes-,- aneh, 221 x workingtool infront. of the-hammer: v 5.In a fluid operated-toohn; body having; separable front and back membersand hay ing acylindertherein formedwvith inlet and;

ing a, hammer, a front'cover plate for-the Y cylinder through; which ithehammer is adapted to project, andigalfioating c-hisel in; front ofthe-cover plate and ha-lnme-r, said exhaust. ports, .a .pistorrinsaidcy-linder ha-yf 3 cover plate and chisel being retained against;

displacement by, the, front membe-nof. the body, thefloatingchiselaatftli e: periphery thereofghaving reverse bevels; extendingaround the .samev and-gthe, front.jmember of thebody presenting abeveled surfacejcor 12o responding with the oppos d-..-b v 1 ofathgsaidchiselQ g I p I 6. In aztool,--abody,- a hammer therein;

means to reciprocate. the hammer, and[a; es.

ciprocating loatingJwor-king tool held in .125 i i the bodyseparatefrom; and in frontofrthe 1 hammer to :be projected:byondtlidbodybyg ablow ofthehammenand.adaptedto h ve a receding movementgunder. pressure.ofrthe work when theliam'mer recedes said. working permittingwthe :1hammers tog 3 5 tool having a front working face, and being name to thisspecification in the presence of tiltagle to general plalne toaccommodzite two subscribing witnesses. itsel to i erent angu arpositions re a- A tively to the body to dispose its front work- DAVIDHALEY SMITH 5 ing face in different planes to conform to the Witnesses:7 surface of the work. WILLIAM E. SEARLE,

In testimony whereof I have signed my 7 T, WATSON.

Copies of this patent may be obtained for five cents each, by addressingthe "Commissioner of Patents, Washington, D. 0.

